Prefolding apparatus



Dec. 18, 1962 H. E. ENGLESON ETAL.

PREFOLDING APPARATUS 6 Sheets-Sheet 1 Filed Dec. 24, 1959 III l I k325i INVENTORSZ HARRY E. ENGLESON E LMER D. SRAMEK Dec. 18, 1962 H. E. ENGLESON ETAL 3,

PREFOLDING APPARATUS Filed Dec. 24, 1959 6 Sheets-Sheet 2 P L :Illlsrv I. I v F,

20 INVENTORS:

HARRY E. ENGLESON ELMER D. SRAMEK Y wMM M Dec. 18, 1962 H. E. ENGLESON ETAL 3,068,761

PREFOLDING APPARATUS 4 Filed Dec. 24, 1959 e Sheets-Sheet s I'll? a0 in man!!! Ilzlll I07 I09 ||o 7 I20 7 10s I A 25 FIGII |05 I04 'INVENTORS:

0 HA'RRY E. ENGLESON ELMER 0. SRAMEK Dec. 18, 1962 H. E. ENGLESON ETAL 3,068,761

6 heets Sheet 4 II M '1@ 84 2'\ i H INVENTORS: HARRY E. ENGLESON ELMER D. SRAMEK Dec. 18, 1962 H. E. ENGLESON ETAL 3,063,761

PREFOLDING APPARATUS Filed Dec. 24. 1959 6 Sheets-Sheet 5 ZNVENTORS: HARRY E ENGLESON ELMER D. SRAMEK Dec. 18, 1962 H. E. ENGLESON ETAL PREFOLDING APPARATUS 6 Sheets-Sheet 6 Filed Dec. 24, 1959 INVENTORS.

ATT'YS HARRY E.ENGLESON ELMER D. SRAMEK 3,053,761 PREFGLDING APPARATUS Harry E. Engleson, Chicago, and Elmer D. Srarnek,

Cicero, Ill., assignors, by naesne assignments, to Cramp ton & Knowles Corporation, Worcester, Mass a corporation of Massachusetts Filed Dec. 24, 1959, Ser. No. 861,2593 Claims. (Cl. 93-49) This invention relates in general to packaging machines, and more particularly to a prefolding apparatus, and still more particularly to a prefolding apparatus for prefolding tray blanks prior to the formation and filling of the tray blanks.

The prefolding apparatus of the present invention receives a tray blank on a table, clamps the tray blank to the table, and folds certain portions of the tray blank over certain edges of the table. Folding bars are employed to fold the portions of the tray blank, and unfolding bars are utilized to unfold the prefolded portions of the tray blank thereby permitting easy removing of the tray blank from the table. Means is provided to accurately position the tray blank on the table to thereby obtain accurate folding of the tray blanks along certain score lines.

Accordingly, it is an object of this invention to pro vide a prefolding apparatus for a packaging machine.

Another object of this invention is to provide a prefolding apparatus for a packaging machine, wherein certain portions of tray blanks are prefolded prior to the formation and packing of the tray blank.

Still another object of this invention resides in the provision of a prefolding apparatus including the table for receiving a tray blank, means for clamping the tray blank to the table, and folding bars for folding certain portions of the tray blank over certain edges of the table.

A further object of this invention is to provide a prefoldin apparatus having means for accurately positioning a tray blank at a folding station in order to properly fold certain portions of the tray blank prior to the formation and filling of same.

A still further object of this invention is to provide a prefolding apparatus having a table for receiving a tray blank in a predetermined position, a clampin plate for clamping the tray blank to the table, folding bars for folding certain portions of the tray blank over certain edges of the table, and unfolding bars for unfolding the prefolded portions of the tray blank and permitting easy removal of the tray blank from the prefolding apparatus.

Other objects, features, advantages of the invention will be apparent from the following detailed disclosure taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. '1 is a perspective View of the prefolding apparatus of the present invention;

2 is 8. pers ective view of the prefolding bars of the apparatus of the p esent invention and also illustrating the manner of driving the prefolding bars;

PEG. 3 is an exploded view of a detail of the present invention illustrating the eccentric mountirn of the prefoiding bar arms;

FIG. 4 is a perspective view, illustrating the tray blank in unfolded position and the manner in which certain portions of the tray blank are folded by the prefoiding apparatus;

H8. 5 is a perspective view of a certain portion of the prefolding apparatus, with certain parts removed for purposes of clarity and illustrating the manner in which the clamping plate is driven;

PEG. 6 is a transverse sectional View, taken substano in 2 tially along line 66 of FIG. 5 and looking in the direction of the arrows;

7 is a sectional view, taken substantially along line 7-7 of FIG. 5;

FIG. 8 is a perspective View, with some parts broken away and other parts in fragmentary condition, and with some parts removed for purposes of clarity, and illustrating the driving mechanism for the pusher-s which remove the prefclded blank from the prefolding table;

FEG. 9 is a detailed fragmentary view, with certain parts exploded, of one of the guide rails on the folding table;

FIG. 10 is an enlarged fragmentary sectional view taken substantially along line ill-ll) of FIG. 8;

FIG. 11 is a perspective view of the driving mechanism for the unfolding bars, with some parts broken away for purposes of clarity;

FlG. 12 is a front elevational view of the prefolding apparatus and illustrating the manner in which tray blanks are positioned on the folding table;

Fl S. 13, 14 and 15 are fragmentary front elevational views of the prefolding apparatus and illustrating steps in the folding operation;

FIG. 16 is an enlarged fragmentary perspective view illustrating the delivery end of the folding table and the relationship of the folding bar and the pushers at that end;

FIG. 17 is a fragmentary transverse sectional view taken substantially along line ISL-17 of FIG; 16;

FIG. 18 is an enlarged side elevational view, illustrating the manner in which the pushers eject a prefolded tray blank from the apparatus; and

FIG. 19 is an enlarged perspective view, partially fragmentary, viewing the under side of the unfolding bar and delivery end of the folding table.

The prefolding apparatus of the present invention may be utilized separately, or in combination with a complete packaging machine, wherein it performs the function of prefolding certain portions of a tray blank to be formed and filled with goods. For example, the tray blanks would probably be delivered from a magazine, one at a time, to the prefolding apparatus for the prefolding operation, and then to a gluing mechanism and to a tray forming and filling apparatus. Prefolding of certain portions of the tray blank permits a better finally formed tray after it has been filled with articles, and also enhances the efiiciency of a packaging operation.

Referring now to the drawings, and particularly to FIG. 1, the prefolding apparatus of the present invention includes generally a folding table 24 which receives a tray blank, a clamp 21 for clamping the tray blank to the table, folding bars 22 and 23 and unfolding bars and 25.

Although the folding apparatus may be designed for folding portions of any type of tray blank, for illustrative purposes, the apparatus as shown prefolds certain portions of a tray blank generally designated by the numeral 25 as seen in PEG. 4. This tray blank includes a bottom 27 having opposed side walls 28 and 29, and end walls 3-3 and El. Flaps 32 extend from the opposite ends of the side wall 23, while flaps 33 extend from opposite ends of the side wall 29. A score line 34 separates the side wall 2%; from the bottom 27, while a score line 55 separates the side wall 29 from the bottom 2?. Similarly, a score line 36 separates the end wall 34? and adjacent naps 32 and 33 from the bottom 27 and the side walls 28 and 29, while the score line 37 separates the end wall 31 and adjacent flaps 32 and 33 from the bottom 27 and the side walls 28 and 29. As seen in FIG. 4, the prefolding apparatus folds side walls 28 and 29 with their corresponding flaps relative to the bottom 27 along the correspond.-

3 ing score lines 34 and 35. Also, the prefolding apparatus subsequently unfolds the side walls 28 and 29 and the corresponding flaps to the, original position, whereby it will be appreciated that the tray blank thereby has certain portions prefolded to enhance the complete formation of the tray blank and the filling thereof.

The folding table 20 is supported on a cantileverly arranged bar 38, FIGS. 8 and 9, that is secured at its inner end to a mounting plate 39 fastened to a frame part 40. The cantilever bar 38 is secured to an L-shaped bracket 41, FIG. 10, by means of a plurality of stud bolts 42, and the bracket 41 is in turn secured to the mounting plate 39 by a plurality of stud bolts 43. At the side of the folding table 20 adjacent the mounting plate 39, a tray blank guide bar 44 is secured to the bracket 41 by means of a plurality of screws 45. The end of the guide bar 44 adjacent the inlet or delivery end of the table 2!} is beveled at 46, FIG. 8, to facilitate centering of the tray blank on the table. Similarly, a guide bar 47 is secured to the other end of the folding table 20 and it is provided with a beveled face 48 opposite the beveled face 46 of the guide bar 44. Thus, a tray blank delivered to the folding table 20 is properly positioned on the folding table along the axis transverse to the path of movement of the tray blank.

As seen in FIG. 7, the delivery end of the folding table 29 is beveled to define a folding edge 49, while the discharge end of the folding table is also beveled to define a folding edge 50. Tray blanks are delivered to the folding table along the upper surface of a pair of pusher bars 51, FIGS. 8 and 12 to 19, by means of a pair of pushing lugs 52 mounted on a pair of transversely spaced endless driven chains 53 (only when shown in FIG. 12). The pushing lugs 52 on the endless chains 53 serve to properly position the tray blanks on the folding table 25).

After the tray blank has been properly positioned on the folding table by the pusher lugs 52, the blank is then clamped to the table by the clamp 21, which includes a clamping plate 54 resiliently mounted on a clamp support 55. The end of the clamping plate 54 adjacent to the delivery end of the folding table 28 is beveled at 56 in order to guide the movement of the tray blank between theclamping plate and the folding table 28 when it is being delivered to the prefolding apparatus. A tray blank retarder in the form of a free floating ball 57 carried in a bore 58 provided in the clamping plate 54 serves to retard the movement of the tray blank as it is positioned on the folding table 20 by exerting a frictional force against the upper surface of the tray blank. If the speed of the prefolding apparatus is slow enough, elimination of the retarder would have no effect on the operation of the machine.

At the four corners of the clamping plate 54, upwardly extending studs 59 are provided which are freely received in apertures formed in the clamp support 55. Coil springs 60 embrace the studs 59 and are bottomed at the lower end on the upper surface of the clamping plate 54 and at their upper ends on the under surfaces of the clamp support 55. Pins 61 extend through the upper veryends of the studs 59 and prevent withdrawal of the studs from the apertures in the clamp support55. Thus, the clamping plate 54 is resiliently mounted on the clamp support 55.

In order to provide vertical reciprocation of the clamping plate 54, a slide bar 62 is secured to the clamp support 55 and slidably supported in guides 63, FIGS. 1, 5, 6 and 12,. the guides 63 being secured to the backing plate 64. The backing plate 64 is fastened directly to the mounting plate 39 by means of outwardly extending rackets 65. The upper end of the slide bar 62 is provided with a laterally extending pin 66 engageable in a slot 67 of the rocker arm 68. The rocker arm 68 extends through an opening 69 in the frame part 48 and is pivotally mounted at 76', FIG. 5, to the frame part 48. The inner end of the rocker arm 68 is pivotally connected to the upper end of a reciprocating push-pull bar 71 having a cam follower 72 mounted thereon and engageable with the cam track 73 of a cam wheel 74. The cam wheel 74 is carriedon a driven shaft 75 connected to the drive of the apparatus. Thus, driving of the cam wheel 74 reciprocates the clamp 21 into clamping and unclamping position. 'It may be readily appreciated that when the clamp 21 is driven to clamping position, downward movement of the clamp support 55 will be greater than the downward movement of the clamping plate 54, thereby resiliently clamping the tray blank to the folding table 28 as shown in FIG. 13. 7

Accordingly, when the tray blank is properly positioned on the folding table 2 the opposite side walls 28 and 29 extend from the opposite folding edges 49 and 5t; of the folding table, whereby the corresponding score lines 34 and 35 substantially co-align with the folding edges 58 and 49, respectively. The folding bars 22 and 2.3 are identical in shape but of opposite hand wherein the folding bar 22 is L-shaped and the folding bar 23 is reverse L-shaped. The folding bars 22 and 23, respectively, include lower flat side wall engaging surfaces 75 and 77 and inwardly extending sharp ends or edges 78 and 79. The edges 78 and 79 are positioned relatively adjacent the folding edges 50 and 49, respectively, of the folding table 28. The folding bars 22 and 23 are positioned as shown in FIG. 12 during delivery and positioning of the tray blank on the folding table 28. Upstanding arms 88 and 81, respectively, support the folding bars 22 and 23 and are driven to impart an eccentric oscillatory motion to the folding bars.

In order to impart the oscillatory motion to the folding bars, the arms 88 and 81 are each pivotally carried in pairs of pins 82, 82, and 83, 83, respectively, which are in turn secured eccentrically to oscillating shafts 84, 84 and 85, 85, respectively, FIGS. 1, 2 and 12. Collars 86, 85 and 87, 87, respectively, maintain arms 80 and 81 on pins 82, 82 and 83, 83. A detailed exploded view of the mounting of the arms on the shafts 84 is shown in FIG. 3, with respect to the arm 80. The shafts 84, 84 and 85, 85 are provided respectively with reduced portions 88, 88 and 89, 89, FIG. 8, that are journaled in vertically spaced bosses 90, 90 and 91, 91 carried by V the mounting plate 39.

Behind the mounting plate 39 and the frame part 40, drive means is provided for oscillating the shafts 84 and 85, wherein pinion gears 92 are mounted on the reduced portions 88 and in engagement with an idler gear 93, and pinion gears 94 are mounted on the reduced portions 89 and in engagement with an idler gear 95. The idler gears 93 and 95 are in engagement with each other, whereby synchronized driving of the oscillating shafts 84 and 85 is thusly accomplished. One of the reduced portion 89 is provided with an extension shaft 96 having a pinion gear 97 mounted thereon and in engagement with a rack gear 93. A cam follower 99 is carried on the rack gear 98 and in engagement with the cam track 188 of a cam wheel 18]. driven on a shaft 192. Thus, driving of the cam wheel 183. reciprocates the rack gear 98 which powers the gears driving the oscillating shafts 84 and 85 thereby imparting an eccentric oscillatory movement to the folding bars 22 and 23. This movement of the folding bars is illustrated in step form in FlGS. 13 to 15 whereby the folding bars serve to fold the side Walls 28 and 29 downwardly and inwardly over the folding edges 49 and 58 of the folding table 20.

In order to permit removal of the prefolded tray. blanks from the prefolding apparatus, it is necessary to provide positive unfolding of the side walls for return of the side walls to the position shown in FIG. 13. This is accomplished by the unfolding bars 24 and 25.

The unfolding bars 24 and 25 are respectively mounted cantileverly on oscillating arms 103 and 184, FIG. 11, which are respectively carried on shafts and 106 journaled in the frame part as. Atoggle linkage arrangement is connected to the shafts which includes levers 187 and 188 secured at one end to the shafts 185 and 106, respectively, and pivot-ally coupled at their other ends to connecting links 109 and 110. The connecting links 109 and 116 are in turn pivotally mounted at opposite ends of an oscillating bar 111 secured at its center to an oscillating shaft 112 journaled in a frame part 113. A drive lever 114 is secured at one end to the oscillating shaft 112 and pivotally connected at its other end to a push-pull link 115. The push-pull link 115 is reciprocated by a cam wheel 116 having a cam track 117 engaging a cam follower 118 carried by the push-pull link 115. The cam wheel 116 is carried on a driven shaft 119. Thus, oscillating movement is imparted to the unfolding bars 24 and 25 by operation of the cam wheel 116. Movement of the unfolding bars is illustrated in FIGS. 13 to 15.

The oppositely extending upper edges of the unfolding bars 24 and 25 are beveled to provide relatively sharp edges 12% and 121, respectively, to facilitate engagement of the prefolded side walls 28 and 29 as seen in FIG. 15. Additionally, the unfolding bar 25 is provided with an upper fiat surface 122 which, as seen in FIG. 13, forms a continuation of the upper surface of the folding table beyond the folding edge 51). Similarly, the unfolding bar 24, when in this position as shown in FIG. 13, provides an extended surface for the folding table 29 ahead of the folding edge 49. In this respect, as seen in FIGS. 16 to 19, raised projections 123 on the folding bar 24 define the extending surface and coact to align in slots 124 formed in the delivery end of the folding table 20. Thus, the unfolding bars 24 and additionally provide extended surfaces for the folding table 20 when in the position shown in FIG. 13.

As already explained, the pusher bars 51 serve as a track or table along which the tray blanks are initially advanced into the prefolding apparatus by the pushing lugs 52 on chains 53. The pusher bars 51 also serve to eject or remove the prefolded tray blank from the prefolding apparatus subsequently to the prefolding operation. In this regard, the pusher bars 51 are notched at their forward ends on the under sides at 125 to define a vertical pushing surface 126, FIG. 18, which engages the trailing end of the tray blank 26. Slots 127 are provided in the delivery end of the table 20 for accommodation of the forward ends of the pusher bars, and grooves 128 are provided in the unfolding bar 25 for accommodation of the pusher bars. As seen in FIG. 18, the overhanging lip 129 of the pusher bars overhangs the trailing edge of the tray blank to prevent it from being displaced to cause malfunction of the pusher member.

The pusher bars 51 are slidably supported on a pair of slide blocks 139, FIG. 8, and connected together at one end by a cross bar 13-1 suspended from an oscillating arm 132. The oscillating arm 13-2 is secured to a shaft 133 suitably journaled in a frame part which is in turn connected to an oscillating lever 134. The oscillating lever 134 is in turn connected to a push-pull link 135 having a cam follower 136 mounted thereon and engageable in a cam track 137 of a cam wheel 138. The cam wheel 138 is driven on a shaft 139. Thus, driving of the cam wheel 138 reciprocates the pusher bars 51 over the slide blocks 131i). The slide blocks 13% are pivotally mounted to a stationary part of the frame, and the positioning thereof is such as to impart an oscillatory motion to the pusher arms of the pusher bars 5-1 during reciprocation thereof. The reciprocatory movement of the pusher bars 51 is such as to advancethe leadi ing end of tne tray blank into the bight of coacting feed rollers 141? which feed the blank to another station in the machine.

It will be appreciated that the cam wheels 74, 1&1, 116 and 138 are synchronously driven from a common drive in order to drive the parts of the prefolding apparatus in timed relationship with each other.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A prefolding apparatus for prefolding a stationary tray blank comprising a table for receiving the blank, said table being smaller than said tray blank, means for clamping said tray blank to said table, means for folding opposite edge portions of said blank downwardly over opposite edges of said table and inwardly beneath the table, and means for unfolding said opposite edge portions and returning same to unfolded position including unfolding bars pivotally mounted beneath said table, said bars having upper surfaces defining extensions on opposite sides of the table when the bars have returned the opposite edge portions to unfolded position.

2. The combination as defined in claim 1, wherein said clamping means includes a clamping plate mounted for vertical reciprocation above said table.

3. The combination as defined in claim 1, wherein said folding means includes folding bars mounted above said table for eccentric oscillating movement.

4. A combination as defined in claim 1, wherein the pivotal mounting of said unfolding bars comprises means for defining oscillating movement of said bars.

5. A prefolding apparatus for prefolding a tray blank comprising a horizontal table, means for positioning a tray blank on said table so that opposite edge portions of the tray blank extend over opposite edge portions of the table, a clamping plate above said table for clamping the tray blank thereto, means for vertically reciprocating said clamping plate between clamping and unclamping position, folding bars for folding the opposite edge portions of the tray blank downwardly over the opposite edges of the table and inwardly beneath the table, means for eccentrically oscillating said folding bars, unfolding bars mounted beneath said table for unfolding said opposite edge portions of the tray blank and returning the same to unfolded position, means for oscillating said unfolding bars, said unfolding bars having upper flat surfaces defining extensions on opposite sides of the table when said unfolding bars have returned the opposite edge portions of the blank to unfolded position, and both said oscillating means being driven in timed relation to each other.

References Cited in the file of this patent UNITED STATES PATENTS 2,477,355 Walton July 26, 1949 2,589,944 Labombarde Mar. 18, 1952 2,739,430 Griswold et al Mar. 27, 1956 

